async_hooks: improve property descriptors in als.bind
The length
property should be non enumerable to match behavior of normal functions.
The asyncResource
property is enumerable and therefore it should be also writable to avoid issues like there: https://github.com/nodejs/node/pull/30932#discussion_r379679982
Both properties should be configurable.
Refs: https://github.com/nodejs/node/pull/34574
fyi @jasnell